SNVSBD3B August   2020  – May 2024 LP8864S-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Logic Interface Characteristics
    7. 5.7 Timing Requirements for I2C Interface
    8.     14
    9. 5.8 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Control Interface
      2. 6.3.2 Function Setting
      3. 6.3.3 Device Supply (VDD)
      4. 6.3.4 Enable (EN)
      5. 6.3.5 Charge Pump
      6. 6.3.6 Boost Controller
        1. 6.3.6.1 Boost Cycle-by-Cycle Current Limit
        2. 6.3.6.2 Controller Min On/Off Time
        3. 6.3.6.3 Boost Adaptive Voltage Control
          1. 6.3.6.3.1 FB Divider Using Two-Resistor Method
          2. 6.3.6.3.2 FB Divider Using Three-Resistor Method
          3. 6.3.6.3.3 FB Divider Using External Compensation
        4. 6.3.6.4 Boost Sync and Spread Spectrum
        5. 6.3.6.5 Boost Output Discharge
        6. 6.3.6.6 Light Load Mode
      7. 6.3.7 LED Current Sinks
        1. 6.3.7.1 LED Output Current Setting
        2. 6.3.7.2 LED Output String Configuration
        3. 6.3.7.3 LED Output PWM Clock Generation
      8. 6.3.8 Brightness Control
        1. 6.3.8.1 Brightness Control Signal Path
        2. 6.3.8.2 Dimming Mode
        3. 6.3.8.3 LED Dimming Frequency
        4. 6.3.8.4 Phase-Shift PWM Mode
        5. 6.3.8.5 Hybrid Mode
        6. 6.3.8.6 Direct PWM Mode
        7. 6.3.8.7 Sloper
        8. 6.3.8.8 PWM Detector Hysteresis
        9. 6.3.8.9 Dither
      9. 6.3.9 Protection and Fault Detections
        1. 6.3.9.1 Supply Faults
          1. 6.3.9.1.1 VIN Undervoltage Faults (VINUVLO)
          2. 6.3.9.1.2 VIN Overvoltage Faults (VINOVP)
          3. 6.3.9.1.3 VDD Undervoltage Faults (VDDUVLO)
          4. 6.3.9.1.4 VIN OCP Faults (VINOCP)
            1. 6.3.9.1.4.1 VIN OCP Current Limit vs. Boost Cycle-by-Cycle Current Limit
          5. 6.3.9.1.5 Charge Pump Faults (CPCAP, CP)
          6. 6.3.9.1.6 CRC Error Faults (CRCERR)
        2. 6.3.9.2 Boost Faults
          1. 6.3.9.2.1 Boost Overvoltage Faults (BSTOVPL, BSTOVPH)
          2. 6.3.9.2.2 Boost Overcurrent Faults (BSTOCP)
          3. 6.3.9.2.3 LEDSET Resistor Missing Faults (LEDSET)
          4. 6.3.9.2.4 MODE Resistor Missing Faults (MODESEL)
          5. 6.3.9.2.5 FSET Resistor Missing Faults (FSET)
          6. 6.3.9.2.6 ISET Resistor Out of Range Faults (ISET)
          7. 6.3.9.2.7 Thermal Shutdown Faults (TSD)
        3. 6.3.9.3 LED Faults
          1. 6.3.9.3.1 Open LED Faults (OPEN_LED)
          2. 6.3.9.3.2 Short LED Faults (SHORT_LED)
          3. 6.3.9.3.3 LED Short to GND Faults (GND_LED)
          4. 6.3.9.3.4 Invalid LED String Faults (INVSTRING)
          5. 6.3.9.3.5 I2C Timeout Faults
        4. 6.3.9.4 Overview of the Fault and Protection Schemes
    4. 6.4 Device Functional Modes
      1. 6.4.1  State Diagram
      2. 6.4.2  Shutdown
      3. 6.4.3  Device Initialization
      4. 6.4.4  Standby Mode
      5. 6.4.5  Power-line FET Soft Start
      6. 6.4.6  Boost Start-Up
      7. 6.4.7  Normal Mode
      8. 6.4.8  Fault Recovery
      9. 6.4.9  Latch Fault
      10. 6.4.10 Start-Up Sequence
    5. 6.5 Programming
      1. 6.5.1 I2C-Compatible Interface
      2. 6.5.2 Programming Examples
        1. 6.5.2.1 General Configuration Registers
        2. 6.5.2.2 Clearing Fault Interrupts
        3. 6.5.2.3 Disabling Fault Interrupts
        4. 6.5.2.4 Diagnostic Registers
  8. 7 Register Maps
    1. 7.1 FullMap Registers
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Full Feature Application for Display Backlight
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Inductor Selection
          2. 8.2.1.2.2  Output Capacitor Selection
          3. 8.2.1.2.3  Input Capacitor Selection
          4. 8.2.1.2.4  Charge Pump Output Capacitor
          5. 8.2.1.2.5  Charge Pump Flying Capacitor
          6. 8.2.1.2.6  Output Diode
          7. 8.2.1.2.7  Switching FET
          8. 8.2.1.2.8  Boost Sense Resistor
          9. 8.2.1.2.9  Power-Line FET
          10. 8.2.1.2.10 Input Current Sense Resistor
          11. 8.2.1.2.11 Feedback Resistor Divider
          12. 8.2.1.2.12 Critical Components for Design
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Application with Basic/Minimal Operation
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
      3. 8.2.3 SEPIC Mode Application
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
          1. 8.2.3.2.1  Inductor Selection
          2. 8.2.3.2.2  Coupling Capacitor Selection
          3. 8.2.3.2.3  Output Capacitor Selection
          4. 8.2.3.2.4  Input Capacitor Selection
          5. 8.2.3.2.5  Charge Pump Output Capacitor
          6. 8.2.3.2.6  Charge Pump Flying Capacitor
          7. 8.2.3.2.7  Switching FET
          8. 8.2.3.2.8  Output Diode
          9. 8.2.3.2.9  Switching Sense Resistor
          10. 8.2.3.2.10 Power-Line FET
          11. 8.2.3.2.11 Input Current Sense Resistor
          12. 8.2.3.2.12 Feedback Resistor Divider
          13. 8.2.3.2.13 Critical Components for Design
        3. 8.2.3.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

4 Pin Configuration and Functions

LP8864S-Q1 DCP Package38-Pin HTSSOPTop View Figure 4-1 DCP Package38-Pin HTSSOPTop View
LP8864S-Q1 RHB Package32-PIN QFNTop View
Product preview
Figure 4-2 RHB Package32-PIN QFNTop View
Table 4-1 HTTSOP Pin Functions
PIN TYPE DESCRIPTION
NO. NAME
1 VDD Power Power supply input for internal analog and digital circuit. Connect a 10μF capacitor between the VDD pin to GND.
2 EN Analog Enable input.
3 C1N Analog Negative input for charge pump flying capacitor. If feature not used leave this pin floating.
4 C1P Analog Positive input for charge pump flying capacitor. If feature not used leave this pin floating.
5 CPUMP Power Charge pump output pin. Connect to VDD if charge pump is not used. A 4.7µF decoupling capacitor is recommended on CPUMP pin.
6 CPUMP Power Charge pump output pin. Always connects with pin 5.
7 GD Analog Gate driver output for external N-FET.
8 PGND GND Power ground.
9 PGND GND Power ground.
10 ISNS Analog Boost current sense pin.
11 ISNSGND GND Current sense resistor GND.
12 ISET Analog LED full-scale current setup through external resistor.
13 FB Analog Boost feedback input.
14 NC N/A No connect - Leave floating.
15 DISCHARGE Analog Boost output voltage discharge pin. Connect to Boost output.
16 NC N/A No connect - Leave floating.
17 LED_GND Analog LED ground connection.
18 LED_GND Analog LED ground connection.
19 OUT4 Analog LED current sink output. If unused tie to ground.
20 OUT3 Analog LED current sink output. If unused tie to ground.
21 OUT2 Analog LED current sink output. If unused tie to ground.
22 OUT1 Analog LED current sink output. If unused tie to ground.
23 NC N/A No connect - Leave floating.
24 INT Analog Device fault interrupt output, open drain. A 10kΩ pullup resistor is recommended.
25 SDA Analog SDA for I2C interface. A 10kΩ pullup resistor is recommended.
26 SCL Analog SCL for I2C interface. A 10kΩ pullup resistor is recommended.
27 BST_SYNC Analog Input for synchronizing boost. When synchronization is not used, connect this pin to ground to disable spread spectrum or to VDD to enable spread spectrum.
28 PWM Analog PWM input for brightness control. Tie to GND if unused.
29 SGND GND Signal ground.
30 LED_SET Analog LED string configuration through external resistor. Do not leave floating.
31 PWM_FSET Analog LED dimming frequency setup through external resistor. Do not leave floating.
32 BST_FSET Analog Boost switching frequency setup through external resistor. Do not leave floating.
33 MODE Analog Dimming mode setup through external resistor. Do not leave floating.
34 DGND GND Digital ground.
35 UVLO Analog Input voltage sense for programming input UVLO threshold through external resistor to VIN.
36 VSENSE_P Analog Pin for input voltage detection for OVP protection and positive input for input current sense.
37 VSENSE_N Analog Negative input for input current sense. If input current sense is not used, please tie to VSENSE_P pin.
38 SD Analog Power line FET control. Open Drain output. If unused, leave this pin floating.
DAP LED_GND GND LED ground connection.
Table 4-2 QFN Pin Functions
PIN TYPE DESCRIPTION
NO. NAME
1 LED_GND Analog LED ground connection.
2 LED_GND Analog LED ground connection.
3 OUT4 Analog LED current sink output. If unused tie to ground.
4 LED_GND GND LED ground connection.
5 OUT3 Analog LED current sink output. If unused tie to ground.
6 OUT2 Analog LED current sink output. If unused tie to ground.
7 OUT1 Analog LED current sink output. If unused tie to ground.
8 INT Analog Device fault interrupt output, open drain. A 10kΩ pullup resistor is recommended.
9 SDA Analog SDA for I2C interface. A 10kΩ pullup resistor is recommended.
10 SCL Analog SCL for I2C interface. A 10kΩ pullup resistor is recommended.
11 BST_SYNC Analog Input for synchronizing boost. When synchronization is not used, connect this pin to ground to disable spread spectrum or to VDD to enable spread spectrum.
12 PWM Analog PWM input for brightness control. Tie to GND if unused.
13 SGND GND Signal ground.
14 LED_SET Analog LED string configuration through external resistor. Do not leave floating.
15 PWM_FSET Analog LED dimming frequency setup through external resistor. Do not leave floating.
16 BST_FSET Analog Boost switching frequency setup through external resistor. Do not leave floating.
17 MODE Analog Dimming mode setup through external resistor. Do not leave floating.
18 UVLO Analog Input voltage sense for programming input UVLO threshold through external resistor to VIN.
19 VSENSE_P Analog Pin for input voltage detection for OVP protection and positive input for input current sense.
20 VSENSE_N Analog Negative input for input current sense. If input current sense is not used, please tie to VSENSE_P pin.
21 SD Analog Power line FET control. Open Drain output. If unused, leave this pin floating.
22 VDD Power Power supply input for internal analog and digital circuit. Connect a 10μF capacitor between the VDD pin to GND
23 EN Analog Enable input.
24 C1N Analog Negative input for charge pump flying capacitor. If feature not used leave this pin floating.
25 C1P Analog Positive input for charge pump flying capacitor. If feature not used leave this pin floating.
26 CPUMP Power Charge pump output pin. Connect to VDD if charge pump is not used. A 4.7µF decoupling capacitor is recommended on CPUMP pin.
27 GD Analog Gate driver output for external N-FET.
28 PGND GND Power ground.
29 ISNS Analog Boost current sense pin.
30 ISNSGND GND Current sense resistor GND.
31 ISET Analog LED full-scale current setup through external resistor.
32 FB Analog Boost feedback input.
DAP LED_GND GND LED ground connection.